• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.15 no.1
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• pp.19-26
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• 2005

In previous report, we presented that petroleum based solvents used in dry cleaning shop was almost similar to stoddard solvent defined by ACGIH and NIOSH, and the occupational exposure standard of stoddard solvent could be used in total exposure assessment of those solvents. The specific aim of the this study was to evaluate of the solvent exposure used in commercial dry cleaning shops by using occupational exposure standard of stoddard solvent. We conducted first survey of 8 self-employed dry cleaning shops and 5 factory type dry cleaning shops from July to August, and second survey of the same shops from October to November in 2002. The exposure concentration to the solvent during loading and unloading activity of vented dry cleaning machine was 489.2ppm(GM), 270.3ppm(GM), respectively, which was almost excursion limit(500ppm) of ACGIH, and exceed the ceiling limit(312ppm) of NIOSH. The time-weighted average (TWA) worker exposure to the solvent was 21.3ppm(GM) at self-employed shops, 20.7ppm(GM) at factory type shops on first survey, and 31.1ppm(GM), 33.7ppm(GM), respectively on second survey. The TWA exposure concentration of workers with spotting and cleaning machine operating job was 25.4ppm(GM), which was 2.9 times higher than the TWA exposure concentration, 8.8ppm(GM) of press workers. All TWA exposure concentrations was lower than OEL(100ppm) of stoddard solvent. We found that the most heavy exposure process at dry cleaning was loading, unloading process, and the vent of dry cleaning machine was the main emission source for workers exposure to petroleum based solvent.

• Journal of the Korean Society of Clothing and Textiles
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• v.12 no.2 s.27
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• pp.207-216
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• 1988

This study is to examine the cleaningproof by dry cleaning runs and parts(shoulder, belly, butt) of garment leathers tanned chrome. This study is composed of three methods of test; color difference test, surface view by scanning electron micrographs, mechanical properties measurement by KES-FB system. The results obtained were as follows: 1. In stiffening of parts of sample, the belly is the best degree in smoothness, fullness, softness. But that of the butt have been found to be the worst degree and to be thick. 2. In fading of parts, the shoulder is an extreme case, but the belly is the best among three parts. 3. In dry cleaning runs, the view after 3 runs has been found to be the best result. 4. The stiffening after dry cleaning 1 run have been low grade, for the sample absorb much solvent of dry cleaning. And, the fading and the decoloration are to be worse after 5 runs. Because the leather surface is affected by dry cleaning runs.

• Textile Coloration and Finishing
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• v.3 no.2
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• pp.10-15
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• 1991

This study was to examine the anti-bacteria effect and the changes of chemical properties of chrome-tanned garment leathers on the preservative treatment. Various test methods, such as investigation of preservative treatment process, resistance test and chemical analysis by cleaning, antbbacterial test by shake flask method are carried out in this study. The results can be obtained as follows: 1. Bacterial reduction percentage of chrome-tanned garment leathers on the preservative treatment was 28.6%. 2. In the antbbacterial effect by dry cleaning, preservative treated leathers has no resistance. 3. Fats content has been removed by dry cleaning using perchloroethylene, so garment leathers properties were altered. 4. PH value was changed by dry cleaning. But once after fats removing, it was changed the little by dry cleaning numbers.

• Clean Technology
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• v.7 no.1
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• pp.13-25
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• 2001

With fast advancement of fine machineries and semiconductor industries in recent decades, the ultra-cleaning of organic chemicals, submicron particles from contaminated unit equipments and products such as silicon wafers becomes one of the most important steps for further advancement of such industries. To date, two kinds of ultra cleaning techniques are used; one is the wet-cleaning and the other is the dry cleaning. In case of wet cleaning, removal of organic contaminants and submicron particles is made by DIW with additives such as $H_2O_2$, $H_2SO_4$, HCl, $NH_4OH$ and HF, etc. While the wet cleaning method is most widely adopted for various occasions, it is inevitable to discharge significant amount of toxic waste waters in environment. Dry cleaning is an alternative method to mitigate environmental pollution of the wet cleaning with maintaining comparable degree of cleaning to the wet cleaning. Although there are various concept of dry cleaning have been devised, the dry cleaning with environmentally-benign solvent such as carbon dioxide proven to show high degree of cleaning from the contaminated porous surface as well as from the bare surface. Thus, special global attention has been placing on this technique since it has important advantages of simple process schemes and no environmentally concern, etc. Thus, this article critically reviews the state-of-the-art of the supercritical fluid drying with emphasis on the thermo-physical characteristics of the supercritical solvent, environmental gains compared to other dry cleaning methods, and the generic aspects of the basic design and processing engineering.

• Laser Solutions
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• v.6 no.3
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• pp.29-35
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• 2003

In semiconductor processing, there are two types of particle contaminated onto the wafer, i.e. dry and wet state particles. In order to evaluate the cleaning performance of laser shock wave cleaning method, the removal of 1 m sized alumina particle at different particle conditions from silicon wafer has been carried out by laser-induced shock waves. It was found that the removal efficiency by laser shock cleaning was strongly dependent on the particle condition, i.e. the removal efficiency of dry alumina particle from silicon wafer was around 97％ while the efficiencies of wet alumina particle in DI water and IPA are 35％ and 55％ respectively. From the analysis of adhesion forces between the particle and the silicon substrate, the adhesion force of the wet particle where capillary force is dominant is much larger than that of the dry particle where Van der Waals force is dominant. As a result, it is seen that the particle in wet condition is much more difficult to remove from silicon wafer than the particle in dry condition by using physical cleaning method such as laser shock cleaning.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.743-746
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• 2000

The removal of contaminants of silicon wafers has been investigated by various methods. Laser cleaning is the new dry cleaning technique to replace wafer wet cleaning in the near future. A dry laser cleaning uses inert gas jet to remove contaminant particles lifted off by the action of a KrF excimer laser. A laser cleaning model is developed to simulate the cleaning process and analyze the influence of contaminant particles and experimental parameters on laser cleaning efficiency. The model demonstrates that various types of submicrometer-sized particles from the front sides of silicon wafer can be efficiently removed by laser cleaning. The laser cleaning is explained by a particle adhesion model. including van der Waals forces and hydrogen bonding, and a particle removal model involving rapid thermal expansion of the substrate due to the thermoelastic effect. In addition, the experiment of wafer laser cleaning using KrF excimer laser was conducted to remove various contaminant particles.

• Journal of Conservation Science
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• v.28 no.3
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• pp.217-228
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• 2012

Damage of cultural properties happens variously. Particularly, the surface damage of metal cultural properties exposed outdoors lowers historical and art historical value of artifact by artificial damage such as paint, scribbling containing oily material and so on. Therefore, this study compared dry-ice pellet cleaning with poultice when clearing paint and oily material environment-friendly, harmlessly to humans and without damage of artifact. As the result of experiment, when clearing those (paint and oily material) by poultice, oily paint was cleared, but there were spots of metal surface. Also, Lacquer spray wasn't well cleared, and resin came off the surface of artifact. When clearing those by dry-ice pellet cleaning, oil paint was cleanly cleared without surface damage of artifact according to Stereoscopic microscope observation, color-measurement, FT-IR, SEM analysis. Also, lacquer spray seemed to be cleared with the naked eye, but there were minute particles on surface according to the result of SEM observation. Consequently, we could confirm possibility of dry-ice pellet cleaning substitution.

• Journal of the Korean Society of Clothing and Textiles
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• v.12 no.2 s.27
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• pp.217-223
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• 1988

This study is to examine the cleaningproof by dry cleaning runs and parts(shoulder, belly, butt) of garment leathers tanned chrome. This study is composed of three methods of test; color difference test, surface view by scanning electron micrographs, mechanical properties measurement by KES-FB system. The results obtained were as follows: 1. In stiffening of parts of sample, the belly is the best degree in smoothness, fullness, softness. But that of the butt have been found to be the worst degree and to be thick. 2. In fading of parts, the shoulder is an extreme case, but the belly is the best among three parts. 3. In dry cleaning runs, the view after 3 runs has been found to be the best result. 4. The stiffening after dry cleaning 1 run have been low grade, for the sample absorb much solvent of dry cleaning. And, the fading and the decoloration are to be worse after 5 runs. Because the leather surface is affected by dry cleaning runs.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.415-419
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• 2002

In this study, we suggest a environmentally-conscious and dry cleaning process mechanism for the recycling of end-of-life CRT, and also develope a protype cleaning system to verify the faulty of the designed mechanism. This system accommodates the specifications of 14 ~ 32" end-of-life CRT. In experimental result, it is expected that the developed system improve the productivity up to 10% and decrease the loss rate of cleaning glass 3~4 times rather than the existing methods.hods.

• Journal of Environmental Health Sciences
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• v.43 no.2
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• pp.95-102
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• 2017

Objectives: This study was conducted to evaluate the emission of VOCs from clothing that had been dry cleaned. Methods: In order to ensure the same conditions, f100% wool scarves were selected as the fabric type. Four identical tests were conducted on the option of either removing the plastic bags which came from the dry cleaning shop or not. The scarf was located inside a closet or room for one or two days. Small chamber tests were conducted to determine the VOC emission characteristics under the same conditions such as temperature, humidity, loading factor, and air exchange rates. Air from the chamber for VOCs was sampled by Tenax TA tube and analyzed by thermal desorption and GC/MSD. Results: Assuming that test represented dry cleaning and consumer's conditions well enough, we can conclude that immediate emissions after the dry cleaning of the scarfs caused elevated levels of TVOC, five VOCs (benzene, toluene, ethylbenzene, xylene, stylene), and decane group compounds. Conclusions: By removing the plastic bags which came from the dry cleaning shop or not, the storage conditions of dry cleaned scarfs by consumers during the storage time periods (one to three days) would be significant for reducing VOC emissions.